Improvement in drills



G. C. TA FT.

Drill.

Patented June- 28. 1864.

` UNITED STATES PATENT Ormea.,

GEORG-E C. TAFT, OF WORCESTER, MASSACHUSETT ASSIGNOR TO THOMAS H. DODGE, OF SAME PLACE.

IMPROVEMENT IN DRILLS.

Specification forming part 0f Letters Patent No. L13,37 2, dated .Tune 28,1864.

To all Awhom it may concern:

Be it known that I, GEORGE C.TAFT,ot` the city and county of Worcester, and State of Massachusetts, have invented certain new land useful Improvements in Drills; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation ofthe same, reference being had to the aeeompanyin g drawings, in which- Figure l represents a perspective view of said drill. Fig. 2 represents a longitudinal vertical section through the saine. Figs. 3, 4, 5, and 6 represent detached views, hereinafter ta be referred to.

My invention relates, principally, to the ap-V plication to drills ot' an adjustable slotted cam in connection with a lever and the i'eedwheel of the drill, whereby the bitor drill is fed to the work automatically, and whereby said feed can be regulated to make it faster or` slower.

`To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

A represents the metal frame of the drill,

i which supports the working parts.

B represents a hollow screw-spindle which plays within the frame A, and can be operated therein to feed the drillfto the work, the ratchet feed-wheel D, by which it is operated, being permanently secured to it. The center spindle, O, is fitted within the 'hollow screwspindle B, and can turn therein freely, and the drill or bit is inserted in the square socket a of the head b. The spindle C is prevented from moving longitudinallywithin the spindle B by the head b, and by the projection c, which bears against the hub of the feedwheel D.

E represents a cam-lever. It is secured at its lower end to the cylindrical rod G, which can slide longitudinally within the ffame A, and the cain-lever turns with said rod as afulcrum. It has a circular slot, d, near its eenter, through which the spindle U passes while it oscillates on its fulerum G. The upper end of the cam-lever E is provided with a hinged pawl, F, which turns ,the feed-wheel D a eertain space to feed the screw-spindle B andthe bit to the work.

H represents a slotted cam which is set in a recess, j', of the eanrlever, and which imparts'to the latter 'the motion by which it aetuates the feed-wheel. The cam H is provided with a pin, m, which ts into one of the holes, 1 2 3, Fig. (i, on the inner side of the hub g of the fly-wheel K. rlhe cam H is thus turned as the fly-wheel revolves, and acts upon the sides of the recess f of the camflever E, and causes the latter to oscillate on its shaft G, and to operate the ratchet feed-wheel D. It is wery essential that said feed should be adjustable to make the machine adapted to working various sizes of drills. This may be done by making the holes l 2 3 at unequal distances from the center of the fly-wheel K, whereby the eccentricity of the pin m, and consequently of the cam H, is adjusted byinserting the pin m in to one of said holes; but to avoid the removing and adjusting of the iiy-wheel for said purpose I use a movable pin-support of the following description: Arecess is cut out in the hub ofthe iiy-wheel K and a pin-support, h, is set therein., which is operated radially by a set-screw, a. The latter is held in position by another set-screw, o, the end of which extends into a neck on the screw n, and on turning the latter the pin-support h is adjusted radially and the pin m et' the cam H, which is inserted therein, ismoved with it, and consequently the eceentricity ot' the cam H, and the length of thestroke ot the cam-lever E and pawl F, is adjusted, whereby the feed of the drill is regulated.

L represents a friction-wheel, Figs. 2 and 5, p

which is s cured to the center spindle, C, by means ofthe projection c, and M is a frictionpawl, which is pivoted at 4 to one of the arms of the ratchet feed-wheel D. The head 5 of the frictionpawl is pressed against the friction-wheel L by means of the spring p, and it is so shaped that when the wheel L is turned in the direction of the black arrow, Fig. 5, no pressure is exerted upon the pawl M, but when turned in the direction of the red arrow the pawl M is pressed upon and binds firmly on the wheel, so as to be coupled to the same. Thus the wheel D and spindle B are coupled to the wheel L, and consequently to the spindie C, when the drivinglpulley K is turned backward and the drill is withdrawn from the hole to renew the operation.

The operation of the drill is as follows On turning the pulley K, which is secured to theI spindle C by means of the projection u, said spindle and the drill are turned. The slotted cam H is operated by being coupled to the hub of the pulley, and operates the cam-lever E, pawl F, and feed-wheel D, the latter turning the screw spindle B to feed the tool. When the hole is drilled, the pawl F is reversed and the motion of the pulley K is also reversed.- The friction-wheelL th us firmly binds the pawl M, and is thus coupled to the feed-wheel D and to the screw-spindle B, and the latter is turned back to withdraw the tool preparatory to a new operation.

Fig. 4 represents a handlever which is to be used in place of the pulley K when the drill is to be operated by hand. Itis also provided with a hub, g, and adjusting-holes l 2 for the insertion ot the eain-pin'm, and with the set-screws q r to secure it to Jche spindle C and to secure the hand'lever N to it.

When a very large balance-Wheel is to 'be used on this drill, the spindle B may be sup ported by friction rolls to avoid the friction of said spindle within the frame A.

Haif'in'g; thus fully described the nature kof my invention, what Iclam herein as new, and desire to secure by Letters Patent, is

1. The movable slotted cam H within the recess of' the lever E, to impart to said lever an oscillating motion, substantially as and for the purposes herein described.

2. In combination with the feed wheel D, the friction-wheel L and pawl M for the purpose otl coupling and releasing the screwspindle B from the drivin 1,-pulley,substan- GEO. C. TAFT.

- Vitnesses:

J. HENRY HILL, ELIZA D. DODGE. 

